Good Medicine can be labor intensive!.
As someone in the profession, I have been on occasion , in the position of the "new trusted" doctor.
I want to say how happy I am that all the diagnostic tests needed to rule out zoonotic and life threatening diseases have been performed. Also, treatment of "occult" parasites ( ones that are not apparent on every stool check) is very helpful. This way, I can be the hero that can now say your dog has a "sensitive system".